Post on 18-Mar-2020
Life Long Learning Aalborg University By Kartheepan Balachandran kba@es.aau.dk
What thoughts we had for the course Like to have feed back afterwards
Would like to make the course interactive so
we avoid this ->
Communication network in smart grid Communication standards Use of existing technologies & research stuff Break Reliability in smart grid Research project: smartc2net Security and privacy
*5 minutes break inbetween each subject
What is Network? People take network for granted, WHY?
Bi-Directional flow of electricity and information
http://venturebeat.com/2010/12/08/smartgrid-europe-renewables/
Wide Area Network Field Area Networks
▪ (Field and Costumer application)
Home Area Networks
Connecting distributed small area networks A form of communicaiton backbone Gets data from Phasor Measuring Unites
(PMU) Transport SCADA data to control center Requirement
Data transfer within the frequency of sampling of the phasor data (PMU)
High bandwidth , low latency
Field based application
Supervisory Control and Data Aqusition (SCADA)
Distributed Energy Resources (DER) monitoring and control
Requirement
Realtime monitoring - Time sensitive
Dedicated network is good but costly
▪ Gives additional security
Costumer based application
Advanced metering Infrastructure (AMI)
Demand Response (DR)
Requirement
Highly scalable network
Time sensitive is not an issue
Doesn’t require a dedicated network
▪ Security has to be implemented
Customer domain:
Monitoring and control of smart devices
Demand Response
Realtime pricing (RTP)
Requirement
Secure two-way communication
Utility public broadcast for event and price signals
Use the internet? Pros: Already deployed
Cons: Reliability?
Deploy dedicated network? Maybe partially? Pros: Secure reliable network Cons: Very costly
What technology do we use? Power line, Wired or Wireless? Maybe a hybrid?
How do we know what technology to use? How do we define requirements for a network? How do we define Performance? What metrics do we use to measure and evaluate
the performance of a network?
Bandwidth
Latency
Jitter
Scalability , availability, QoS
Consequence of low bandwidth? Bottle neck
High delay
Packet loss
Wide area network requires Bandwidth
It act as a backbone network to connect all small area networks
Have to transfer large amount of data
Data collection from PMU’s
Case study:
If I have 10 Mbit internet connection, will I be able to deliver the data needed for smart grid?
Keyword: Delivery
Truck analogy
▪ Is it okay if I use a truck to send 1000 memory sticks of 2 MB of data to france but it will take 2 days to be received?
▪ Or do we prefer to send 2GB in less time?
IP over Avian Carriers ▪ Proposal to carry IP traffic by birds eg. Homing pegeons.
▪ RFC 1149 by D. Waitzman 1 april 1990
▪ Later improved the protocol with RFC 2549 IP over Avian Carriers with QoS
IPoAC has been successfully implemented, but for only nine packets of data, with a packet loss ratio of 55% (due to user error),[2] and a response time ranging from 3000 seconds (~54 minutes) to over 6000 seconds (~1.77 hours). Thus, this technology suffers from poor latency. Nevertheless, for large transfers, avian carriers are capable of high average throughput when carrying flash memory devices
Source: http://en.wikipedia.org/wiki/IP_over_Avian_Carriers#cite_note-1
The time it takes a packet to reach its destination and get back an acknowledgement (depending on the protocol)
The communication between the customer and the utility company is not time sensitive
Measuring the grid status require realtime data and require therefore low latency
Spikes in routing/switching delay Jitter can give spikes of latency Eg. caused by bittorrent which opens many
communication channels and thereby overload the routers scheduling mechanism
Gives data loss which can be experienced in phone conversation.
Not good for real time application
Prioritisation of traffic ISP setup QoS on router for VoIP service QoS might also be necessary if we want to use
the internet to send meter data or do Direct load control at the Customer.
Reliability Network must not go down
Delay sensitive Time sensitive data must be able to reach
destination Security
The network must be resilient against attacks and manipulation and ensure privacy
Cost efficient Must not be costly to deploy the network
Requirement Have to understand the problem to be able to set up
requirements
Understanding delay components The network will consist of many different network
tech. And components which introduce different delays in the system
Minimizing end-to-end delay Network tech. Selection and protocol development to
speed up time urgent messages.
In the end we want to avoid this from many point of views:
Standardisation activities
Guides for development of next generation electric power systems.
The ”famous” standards
▪ IEC Standards
▪ IEEE Standards
▪ ANSI
IEC - International Electrotechnical Commission IEEE - Institute of Electrical and Electronics Engineers ANSI - American National Standards Institute
IEC 61968-9 and 61970 (energy man. Syst.)
▪ Defines the common information model for data exchange between devices and networks in the power distribution domain and the power transmission domain respectively.
IEC 62351 (information security)
▪ Defines the requirements to achieve different security objectives including data authentication, data confidentiality, access control and intrusion detection.
IEC 60870-6 (Inter-control center communiation)
▪ Data exchange between utility control center, utilities, power pools, regional control centers.
Source: W. Wang et al. / Computer Networks 55 (2011) 3604–3629 GÜNGÖR et al.: Smart grid technologies: communication technologies and standards
IEC 61850 (appl. Substation automation):
▪ Defines the communication between devices in transmission, distribution and substation automation systems.
Source: W. Wang et al. / Computer Networks 55 (2011) 3604–3629
IEEE P2030 (Customer side appl.)
▪ A guide for smart grid inter-operability of energy technology and IT operation with the electric power system.
IEEE P1901 (Home area network)
▪ High pseed power line communication for in-home multimedia, utility and smart grid application
IEEE 1547 (Field area network for D.E.R)
▪ Defines and specifies the electric power system that interconnects distributed resources.
Source: W. Wang et al. / Computer Networks 55 (2011) 3604–3629 GÜNGÖR et al.: Smart grid technologies: communication technologies and standards
IEEE 1646 (substation automation)
▪ Defines communication delivery times to substation. It also discuss the system and communcation capabilities required to deliver real-time support, message priority, data critcality and system interfaces.
Laverty, D.M. et al.: Practical evaluation of telecoms for Smart Grid measurements, control and protection
Source: GÜNGÖR et al.: Smart grid technologies: communication technologies and standards
ADSL WiMAX 3G/LTE FTTH GSM PLC
Two types of medium can be used, eg.
Wireles and wired.
Two types of information infrastructure are needed for information flow in smart grid system.
1. From sensor and electrical appliances to smart meters
2. From smart meters to the utility’s data centers.
From sensor to smart meter can be achieved by e.g.: PLC
▪ Advantage: Existing infrastructure, cost-effective, already used in HAN. ▪ Disadvantage: transmission are broadcasting, critical from security
aspect, the medium is noisy, effected by number and type of devices connected to the powerline, wiring distance between transmitter and receiver affect the quality of the transmitted signal.
ZigBee ▪ Advantage: Low power, range from 1-100m, low cost deployment and
standardized protocol IEEE 802.15.4
▪ Disadvantage:low processing capabilities, small memory size, subject to interference (2.4 Ghz), can be easily currupted by WiFI, Bluetooth and Microwave
Source: GÜNGÖR et al.: Smart grid technologies: communication technologies and standards
To send data from smart meter to data centers Cellular technologies
▪ Advantage: GSM, GPRS, UMTS, WiMAX, 3G, LTE already exist. No extra cost to build infrastructure. Widespread cost-effective benefits. Can reach rural areas. Low maintenance cost
▪ Disadvantage: power grid mission-critical applications need continuous availability of communication. The cellular networks are shared by customer market. Network congestion or decrease in performance can happen.
DSL
▪ Advantages: widespread availability, low-cost and high bandwidth data transmissions.
▪ Disadvantages: Reliability and potential down time may not be acceptable. Not reachable on rural areas due to high deployment cost
Source: GÜNGÖR et al.: Smart grid technologies: communication technologies and standards
Source: GÜNGÖR et al.: Smart grid technologies: communication technologies and standards
Laverty, D.M. et al.: Practical evaluation of telecoms for Smart Grid measurements, control and protection
Smart Grid Net simulator Reliable choice of Aggregator for connecting
Electric Vehicle to the Smart Grid
The metadology approach is building a smart grid simulator
We want to enhance a network simulator with smart grid communication features
Analysis of a specific usecase
Lookup for potential
aggregators
Fetch information
and decide on aggregator
Connect to aggregator
Waiting time (tw)
Delay 2 Delay 1 Aggregator1
Aggregator2
Aggregator3
DER
X
X
X X
X
X
X
Model: -Stationary processes
-Indepence and identic
distributed
Key parameters that impacts reliability
- Event interarrival times
- Communication delay btw. Aggregators and DER’s
- Waiting time
Aggregator 1 (Avg): Delay 70 ms,
Event time 78 sec.
Aggregator 2 (Avg) Delay 50 ms
Event time 18 sec.
Aggregator 3 (Avg) Delay 531 ms
Event time 20 sec.
Aggregator 4 (Avg) Delay 829 ms
Event time 92 sec.
Aggregator 5 (Avg) Delay 732 ms
Event time 25 sec.
How long shall we wait?
Optimal waiting time